A known fluoroscopy device in the related art radiates excitation light, which generates fluorescence by exciting a fluorescent agent that preferentially accumulates in a lesion, such as cancer cells, onto an observation site that is administered the fluorescent agent. The fluoroscopy device photographs the generated fluorescence so as to acquire a fluorescence image of the lesion (for example, see Patent Literatures 1 to 3).
The fluoroscopy device discussed in each of Patent Literatures 1 to 3 divides the fluorescence image based on the intensity of the fluorescence generated in the observation site irradiated with the excitation light by a reference image based on the intensity of return light returning from the same observation site irradiated with white light so as to correct a variation in fluorescence intensity, which is dependent on the observation distance, the observation angle, etc., in the fluorescence image.